Internal Cleanliness of Steel Vessels for High Purity Applications

Many steel pressure vessels are utilized for the global shipment of electronic-grade gases, such as silane, NF3, HCl and N2O, which are used for the manufacturing of semiconductor materials. The purity of this gas is paramount to semiconductor quality because impurities can be detrimental to the manufacturing of silicon wafers.  FIBA has developed and validated processes to internally clean and even polish the walls on the internal surface of the tube.  These processes will minimize the presence of hydrocarbon and particulate contaminants that will negatively affect gas quality.

Internal CleaningInternal Cleaning of Tube

After internal shotblasting to remove large contaminants from the tube heat-treatment processes, the tubes are thoroughly internally cleaned with specialized solvents to remove any hydrocarbons.  They are then flushed with heated, de-ionized water to remove any residual solvent and particulates.  Non-volatile residue (NVR) testing (performed gravimetrically) and particulate population counts are often performed by FIBA to validate the internal cleanliness of the tube.

nvr-inspection-tubeFIBA QA Technician performs NVR & Particulate counts

For aggressive gases or gases that require passivation the internal surface of the tube can be polished to a 20 RA microinch finish or electrolytically nickel plated.

polish tube interior surfacePolished Tube Interior Surface

FIBA can offer such cleaning services for individual cylinders (e.g. ton containers) and large tubes comprising tube trailers and multiple-element gas containers (MEGCs).

William O’Brien has worked at FIBA since 1978 and has held many positions within the company, including Vice President of Operations and most recently Vice President of Plant Operations, Service Division. Bill is regularly consulted by the industrial gas community and serves on the CGA Cylinder Valve Committee.

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